Mold form for circular concrete walls



March 21, 1939. w. A. JENNINGS v MOLD FORM FOR CIRCULAR CONCRETE WALLS Filed April 3, 1956 2 Sheets-Sheet 1 m 3 3; e mw 4 1 v 1 w :M 0 5 w 1 1 2 4 z i 1 5 March 21, 1939. w A JENNINGS 2,151,210

MOLD FORM FOR CIRCULAR CONCRETE WALLS Filed April 3, 1936 2 Sheets-Sheet 2 Patented Mar. 21, 1939 UNITED STATES MOLD FORM FOR CIRCULAR CONCRETE WALLS William Allen Jennings, Des Moines, Iowa, as-

signor to Economy Forms Corporation, Des Moines, Iowa, a corporation of Iowa Application April 3, 1936, Serial No. 72,561

3 Claims.

My invention relates to the art of metal forms for concrete structures and specifically that class of metal forms disclosed in my Patent No. 2,046,123, issued June 30, 1936, in which there is disclosed a form capable of use interchangeably for either straight or curved concrete structures.

In many concrete structures, there are portions which are straight and other portions curved. It has been the practice to provide one set of flat rigid forms for the straight portions and another set or" bendable or curved forms for the curved portions. of the structure.

My object is to provide a form of this character y of. simple, durable, and inexpensive construction in which the same forms may be used interchangeably on either straight or curved concrete structures, and repeatedly reused, and which will be firmly braced and reinforced to withstand the pressure of the concrete when used in straight,

outwardly curved or inwardly curved concrete structures.

More specifically it is my object to provide a panel of this class in which the body portions and flanges are all formed of a single piece of relatively thin and inexpensive sheet metal, with braces fixed to the body portion to hold it substantially flat and relatively unbendable and other braces secured to the outer portions of the flanges to make them relatively unbendable and suitable for the application of clamping devices, and whereby when the body portions are bent or inclined inwardly relative to a concrete structure being formed substantially all of the bending will occur along a narrow line between the braces of the body and the braces of the flanges so that only thin and short ribs of concrete will be formed on the concrete surface at the points where the flanges of the panels are thus separated when bent to form curved surfaces.

Referring to the accompanying drawings:

Figure 1 shows a perspective view of one of my improved panels.

Figure 2 shows a top view of two panels connected by a clamp and inclined relative to each other to form a curved concrete structure.

Figure 3 shows a perspective view illustrating the adjacent corners of two panels in position bent to form a curved concrete structure.

Figure 4 shows an outer face view of two panels with their adjacent flanges clamped together and the panels bent to form a curved concrete structure and illustrating the bends at the end portions of the flanges.

Figure 5 shows a top view of the adjacent corners of two panels illustrating the notches formed in the corners of the flanges.

Figure 6 shows a top view of the adjacent portions of two panels bent to position for forming an outwardly curved concrete structure and two similar panels bent to form the inwardly curved concrete structure for the opposite side of the concrete structure.

Figure 7 shows an end elevation of the adjacent portions of two panels clamped together with the panels bent to position for forming an inwardly curved structure. The dotted lines show the panels in position for forming a straight wall; and

Figure 8 shows a similar view with the panels bent to position for forming an outward curve. The dotted lines show the position of the panels for forming straight concrete walls.

The entire panel and its flanges is formed of a single piece of resilient sheet metal relatively thin and relatively bendable so that of itself it would not be rigid enough to withstand the pressure of the concrete. The body of the panel is flat and rectangular as indicated at I0, and all four edges are bent outwardly to form integral flanges ll.

At their outer edges these flanges are braced or On the outer surface of the panel there are a number of braces l3 fixed to the panel and serving to prevent the body portion of the panel from bending under pressure from the concrete. All of these braces are operatively disconnected from each other preferably by having their ends beveled asshown. at I4 and whereby the flanges may be bent or inclined slightly from their normal positions at right angles to the panel.

Formed in the flanges is a series of openings to receive clamping devices such. as bolts or a. clamp comprising a pin l5 to enter the openings i5 in two flanges, connected to two jaws E1 to engage opposite faces of the flanges and securely ciamp them together. A clamp of this kind is more fully disclosed in my said patent.

In practice and when it is desired to build a straight concrete structure, the panels are placed in alignment and clamped together and supported in an ordinary manner; when this is done the outward pressure upon the panels will not bend l them because of the braces and flanges and they are used in the same manner as ordinary flat rigid metal panels.

When, however, it is desired to form a curved concrete structure the flanges are clamped together in the same way and an entire series of panels is bent to form substantially the curve desired, then the panels are fixed in an ordinary manner in this position. Vfhen this has been done the bodies of the panels will remain flat and braced against pressure from the concrete and all of the bending will be between the inner edges of the braces l2 and the ends of the braces 13 and flanges II. It is only along this narrow line that bending of the panel can occur.

I have used the term curved concrete structures herein. In reality when such walls are made with my improvement they consist of a series of flat surfaces at slight angles relative to each other. In practice, however, I have constructed numerous of such structures which were specified as curved and have had them accepted as being the full equivalent of curved surfaces.

In practice I have found that in many concrete structures there are some straight surfaces and some curved surfaces to be constructed. It has .been customary to provide one set of flat forms for the straight surfaces and another set of curved or bendable forms for the curved surfaces. In practice these' forms are used repeatedly on the same structure to form portions of the structure at one time and other portions at a later time. In view of theforegoing I find in actual practice that in erecting .a certain concrete structure I employ only about half the panel units that were previously necessary and thus effect a very substantial saving, because I use the panels first on the straight portions of the structure and then reuse the same panels on the curved portions. After the panels are used for curvedstructures then upon their removal the resilience of the sheet metal at once; causes them to straighten out with the flanges at right angles to the body portions and ready for use on straight structures.

In the modified form illustrated in Figures 3, 4, 5 and 6 I have disclosed mold forms having the desired flexibility for forming curved concrete structures and at the same time having the advantage of being capable of withstanding all of thestrains and stresses to which they are subjected when in use, without buckling or distortion. To accomplish this purpose I have placed in each corner a block l8 preferably of cast metal, in engagement with both adjacent flanges l I and extended outwardly substantially half the width of the flange, and the flanges are welded to this block and to each other. The ends of the flanges beyond this welded portion are disconnected and are inclined slightly, as shown at IS in a direction away from each other, that is to say when the flanges of two panels are placed together their outer edges will be slightly separated. This welding of the corners together gives to the flanges such rigidity as will withstand all buckling strains or distortions when in use, and yet will permit the use of those panels in curved concrete structures. 'As shown in Figure 6 the two panels are slightly inclined relative to each other and the necessary bending of the metal to permit this bending takes place in the flanges between the clamps and the corners as illustrated at l9. For the purpose of permitting two adjacent panels to be bent to form an inwardly curved structure as shown at the bottom of Figure 6, I provide notches or cut away porshown at the top in Figure 6 so that in two ad-} jacent panels they will be slightly separated,

two adjacent panels may be bent to positions 1 with the flanges inclined away from each other at their outer edgesthus avoiding all tendency to buckling of the flanges, and thereby providing a mold form which may be repeatedly reused and not be damaged or distortedby the strains and stresses to which these panels are subjected.

I claim as my invention: 7

l. A form for concrete structures, comprising a series of panels each made of bendable sheet I metal having one edge bent outwardly to form a flange, means for reinforcing or bracing the body portions of the panel to make it substantially flat and relatively unbendable, means for reinforcing and bracing the flange from a line slightly spaced from the body of the panel toward the outer edge of the flange, means for clamping together the braced or reinforced portions of two adjacent flanges, thereby leaving the sheet metal between the reinforcements of the panel and the reinforcements of the flange relatively bendable, and whereby when two adjacent panels are bent along said line the inner faces of the panels will be only slightly separated. I

2. In a mold form for concrete structures, the. combination of a panel member formed of bend-- able materialv and having its side edges inclined outwardly from the body of the panel to form flanges, the outer edge portions of the flanges being folded backwardly toward the body of the panel .and terminated substantially midway between their inner and outer edges to form a nonbendable reinforcement, and means for reinforcing the body portion ofthe panels toprevent bending, whereby the bending movement of the panel is limited to those portions thereof between the reinforcements of the flanges and the reinforcement of the body. 7

3. In a mold form for concrete structures, the combination of a panel formed of bendable metal, its edge portions being bent outwardly to form flanges, braces fixed to the panel. and extended across the panel to points adjacent but spaced apart from the side flanges and said side flanges being disconnected .at their ends from the upper and lower flanges, whereby the body of the panel will at all times be maintained in flat condition and the side flanges may be bent outwardly or inwardly relative tothe body of the panel, and a stiffening block fixed in position at one corner of the panel and also fixedly con nected to both of the adjacent flanges at points spaced from the outer edges of the flanges, for the purposes stated. 7

WILLIAM ALLEN JENNINGS. 

